Conventional pouring control methods with an automatic pouring device with a tilting-type ladle are shown as follows: Patent document 1 discloses a method for storing data on a pouring flow rate that is obtained when the operator pours the molten metal (outflow weight from the pouring ladle per unit of time). The ladle tilting angular speed is adapted such that the pouring flow rate by the automatic pouring device is equal to the pouring flow rate by the operator. Patent document 2 discloses a method for achieving a relationship between the ladle tilting angle and the pouring flow rate from the result of preliminary test pouring experiments and adjusting the ladle tilting angle to achieve a desirable pouring flow rate pattern. Patent document 3 discloses a method for carrying out a feedback control such that the level of the surface of the liquid at the sprue of the mold is constant.
However, these pouring control methods require many test pouring experiments to determine control parameters. In particular, since the relationship between the control parameters and the physical parameters (the shape of the pouring ladle, the flow rate coefficient, and the liquid density) related to the pouring process is unclear, similar test pouring experiments are required for the pouring process where a different type of shape of the pouring ladle and a different type of liquid to be poured are used. In addition, if the test pouring experiments and the pouring environment change, for example, a characteristic variation of the liquid to be poured due to the decrease in temperature of the molten metal, etc., and/or the variation of the shape of the pouring ladle caused by accumulating slag, occurs, then a decrease in the accuracy of the pouring becomes a problem.
For this reason, the inventors of the present invention derived the mathematical model of the pouring process based on fluid mechanics, and developed the model-based pouring control system (Patent documents 4 and 5). It was a pouring control system based on that model. Since the relationship between the physical parameters and control parameters of the pouring process in that control system is clear, even the small number of pouring experiments allowed one to build the control system for the automatic pouring device where a different type of shape of the pouring ladle and a different type of liquid to be poured are used.